1. The therapist should be trustworthy, competent, and caring.
2. The therapist should facilitate behavioral modification in the patient by fostering hope and "stimulating emotional arousal" (as Millon puts it). In other words, the patient should be re-introduced to his repressed or stunted emotions and thereby undergo a "corrective emotional experience."
3. The therapist should help the patient develop insight about herself - a new way of looking at herself and her world and of understanding who she is.
4. All therapies must weather the inevitable crises and demoralization that accompany the process of confronting oneself and one's shortcomings. Loss of self-esteem and devastating feelings of inadequacy, helplessness, hopelessness, alienation, and even despair are an integral, productive, and important part of the sessions if handled properly and competently.
(From the book "Malignant Self-love: Narcissism Revisited" by Sam Vaknin - Click on this link to purchase the print book, or 16 e-books, or 2 DVDs with 12 hours of video lectures on narcissists, psychopaths, and abuse in relationships: http://www.narcissistic-abuse.com/thebook.html)